So I've been getting this engine stutter for quite some time now, it stutters really bad when I'm at idle, but the engine seems to hesitate under low RPM load and acceleration sucks.

I've replace the following;
MAF
Spark Plugs
TPS

Cleaned;
IACV
Throttle body

Dealership Checked;
Coil Packs
and spent another 4 hours doing diagnostics (unsuccessfully)

I've got no ECU codes, and I was getting a Throttle Sensor Circuit code off the Trans.

I just replaced the TPS last night, and the resistance is bang on 500 ohms/4000 ohms, but according to this http://vbxmaxima.8m.com/tps.html I'm supposed to be getting 5V off pin 1, but I'm getting 0V.

Any Ideas?

Thanks

 

have you checked your injectors?

 

Yes....sorry also checked by dealership.

They said my fuel mixture was too high under 3000rpm, citing the MAF was the culpret as both O2 sensors reported the same values, so instead of buying a $700 part new (canadian prices suck for MAF) I got one off the org here for $50.

 

Anyone?

 

I too have the same problems but I intermittently get codes for the Camshaft Position Sensor (Replaced) and the Crankshaft Position Sensor (REF Only), but the MIL never comes on. I have a reader hooked up while its running and the codes pop up, sometimes one or the other, sometimes both, but the MIL never pops on. When I start the car for the 1st time of the day, it seems to run fine, but as it warms up, RPM's start to fluctuate by about 600 at idle. In addition to some of the work you have done, I checked the PCM for corrosion at the pins (none).

My only suggestion is to un-hook your battery, as this will reset your PCM.

 

I had engine stuttering as well and got a CEL light saying my cylinder was misfiring.
Was using 89 octane at the time. Put in 91 octane. Was fine for a little bit then started to stutter again.

I Seafoamed the SOB.
2 cans of seafoam. 1 for the gas tank and 1 for the intake/exhaust system. When I get my oil changed I'll be Seafoaming the oil tank as well.
No more misfire and I just reset the code and no more CEL and I've driven her 60-65 miles.

So if you have $8 to spare at autozone you could give it a try. No guarantee that it'll stop the shaking but it worked for me. The directions are on the bottle. Should be in the section with all the cleaners. (injector cleaner, throttle cleaner, etc)

 

Thanks for the 2 suggestions....I'll be giving them a try today/tomorrow.

 

Seafoam will do nothing but fk it up more.

 

Have you checked your coolant temp sensor?

 

Funny you say that since my engine problems went away afterwards. I guess -if- you've tried to seafoam then you didn't do it right.

How would seafoaming the car fk it up more? O.o

 

Would this be caused by a faulty / toasted cat? With 330,000 KMS, (200,000 miles), I've never replaced it.....

I plugged in an OBDII reader and it showed catalytic monitor fault....essentially that the downstream O2 sensor was reading the same as the upstream O2 sensor, indicating a faulty cat? But no trouble codes were present.

 

ive foamed my max a few times diffrent ways over the past 25K miles and ive had nothing but good things come from it. i know alot of people have diffrent oppinons on it but mine is good. the only thing i can think it could cause is a fk'ed 02 Sensor. and ive already got one of those so haha who cares lol.

 

I know this thread is old but the question never got answered. Pin 1 on the TPS isn't going to show voltage without power going to it. You are supposed to check for 5v on pin/socket 1 on the TPS wiring harness plug.

 

Get a second opinion. My dealership told me that it wasn't coil packs, I went to a local shop that I heard was good, right away they said it was a coil pack. They showed it to me, the coil pack was melting. o_O

 

well my engine did the same, but my problem was that i had a spark plug connector wire short, try playing with the connector wire to see if theres a short...

 

I've checked all the coil packs myself and I don't see any short/melting....they all check out with proper ohmage.

I've got a ground wire just before the CAT that is hanging loose, have to get that checked out too.

 

What year is your car?

If it were me or someone who brought it to me, I would say that BOTH of the 2 front primary o2 sensors should be replaced before doing anything else. 200K is WAY past there lifetime, plus the reading nissan got from the scanner hints that they are not reading correctly.

 

it's a 96/

well i have replaced the rear one about 2 yrs ago, just not the front one...I'll probably do that once I put in the Cat and Y-Pipe.

 

Interesting... I'm seeing a very similar bunch of symptoms on my 1995 5spd with 140k... I, too, have a faulty ground wire on the CAT O2 sensor (it's pretty much hanging off the car). I wonder if this could be an issue...